1. Field of the Invention
This patent discloses a completely new category of rotary systems, motors and generators. The disclosed invention employs highly-integrated innovations cutting across multiple fields of innovations, including: magnetic actuators, electromagnetic rotary machines (specifically variable reluctance motors and generators), gear (speed) reduction/torque enhancement systems, electronic controllers, power circuitry, feedback control systems, and fully-integrated drive systems. This invention is indeed a system where everything from the controller to the wheel, or central shaft, is integrated into a single device to maximize efficiency while minimizing weight, size and cost. This integration across multiple fields of innovation blurs the lines between controller, motor, speed-reduction/torque enhancement system and wheel (or shaft), with motor components being used as controller components, speed-reduction/torque enhancement components, and as a wheel rim or other uses for a revolving element.
However, first and foremost, the invention belongs within the combined fields of magnetic actuators and electromagnetic rotary machines. Where the invention is a hybrid of the basic components of each: actuators and armatures typical of actuated devices, as well as a stator and rotor typical of a rotary device. The actuators of this invention form the circular structure of a stator, and the armatures associated with these actuators are merged into a single continuous flexible circular band of high magnetic permeability that acts as a rotor.
2. Prior Art
Alfred Kreidler [1], FIG. 4, is perhaps the closest prior art to the actuators employed in the herein disclosed motor/generator. [1] Shows a curved actuator surface 13 and continuous rolling armature 14 with a spring 11 to “spring” the armature away from the actuator surface when the actuator turns off.
The actuators of the herein disclosed invention do have a curved surface, and the armature does curve to conform with that surface when the actuator is activated; further, the armature of the disclosed invention does spring away from the actuator when the actuator is turned off. However, the disclosed invention differs as follows: it employs multiple actuators with curved surfaces placed side-by-side to form a complete circle; employs a single circular band that acts as a single armature for all the actuators; employs an armature that is flexible and only in this way is able to conform to the curvature of the actuator surfaces; employs an armature that has its own efficient spring characteristic, thus eliminating the need for an external spring; and most importantly, mechanically links the continuous rolling motion of the armature to a surrounding rim or central shaft, therefore the disclosed actuators can never function separately but must be synchronized with each other.
Electromagnetic Rotary Machines (Motors and Generators)
Michael Faraday designed and constructed the first electric motor in 1821, [2]. Since then, many types of electromagnetic rotary machines have been developed using the principles of magnetic fields and what is empirically know about magnetic materials: permanent magnets and magnetically permeable materials. There are many types of motors that employ electromotive forces: DC, AC, synchronous, field effect or induction motors, permanent magnet, hysteresis and switched reluctance, [3]. All electric motors consist of a stator, which remains stationary, and a rotor that turns either within or about a stator. The stator is comprised of electromagnetic circuits that can be switched on and off as appropriate to propel the rotor. The rotor is comprised of either: permanent magnets, semi-permanent magnets (as in the hysteresis motor), electromagnets, self-induction elements (induction motor) or permeable magnetic materials (switched reluctance motor) [5]. The switched reluctance motor is unique, as it is the only type of motor that employs a “passive” rotor—a rotor without any magnetic poles. Instead the rotor of reluctance motor acts to complete the magnetic circuit between magnetic poles produced in the stator.
In every case, the purpose is to employ magnetic fields to produce forces tangent to the direction of rotation of the rotor surface that cause the rotor to turn. The electromagnetic fields produced by the stator are switched on and off, or otherwise cycled (e.g., with the application of phased alternating electrical currents) in such a fashion that the attractive and repelling fields produced by the stator move around the stator surface so as to continue to apply tangential forces to the rotor. Finally, there is always an air gap between the rotor and stator the size of which limits the magnitude of the tangential forces produced—the amount of force applied to the rotor that makes it turn. This air gap must be mechanically maintained and supported so that the moving rotor cannot contact the stator surface, which would damage the motor in all existing designs.
Ten years after Michael Faraday developed the first motor a crude generator, and the first alternating current generator that could be put to practical use was developed by a Belgian-French inventor by the name of Zenobe Theophile Gramme in 1867; the same Gramme developed a direct current generator in 1869.
Within the above-described field of electromagnetic machines (motors and generators), the switched reluctance (SR), sometimes called variable reluctance (VR), machine is prior art most closely associated to the disclosed invention. The SR machine can be operated as either a motor or a generator. The SR machine does not use either permanent magnets or electromagnets in the rotor to create attractive and repelling forces to move the rotor. Instead, the rotor of a switched reluctance motor is passive, employing highly permeable magnetic material that acts as a magnetic conduit to link salient north and south electromagnetic stator poles. While in most SR motors, the rotor is comprised of salient “poles;” again, these are passive (not being magnetized as either north or south magnetic poles) and are physically spaced such that torque to turn the rotor is created as the rotor poles are pulled by magnetic forces of attraction into alignment with north and south electro-magnetic poles created by the stator windings. This is called a “switched” reluctance motor because as soon as the salient poles of the rotor come into alignment with one set of electromagnetic north and south poles of the stator (a low reluctance state), those poles are switched off and a neighboring set of north/south poles in sequence around the stator surface is switched on (a high reluctance state), and the rotor is attracted forward toward those poles, etc.
The herein disclosed invention differs from existing SR motor art in five fundamental ways. First, unlike any existing SR motor, the rotor of our invention has no salient poles. Instead the rotor of the invention is a perfectly smooth band of highly permeable material. Second, the rotor of the invention is flexible and continuously changing shape as the motor runs; whereas SR rotors are rigid and does not change their shape. Third, in operation the flexible rotor of the disclosed invention is pulled into contact with the stator surface and is “force wrapped” forward (or backward) along the stator surface, whereas the rotor of a SR motor (or any other electric motor) never contacts the stator surface. Fourth, unlike any other motor (SR, or otherwise), the invention employs radial forces—the forces of attraction between the rotor and stator—as the primary motive force to turn the rotor; all other motors employ forces tangent to the direction of rotor rotation. Fifth, unlike any rotor of any other motor, the forward (or backward) “force wrap” movement of the flexible rotor around the stator acts as a differential speed-reduction/torque-multiplying mechanism, lowering output speed and increasing output torque. This is a discovery the inventors made and used with elements for a given purpose therefore it can be given a claim at no cost thus there can be a “gearing” at no cost and no additional weight.
Gear Reduction Systems/Drive Trains
There is a great deal of prior art for gear reduction systems and drive trains. However, the only patented invention that comes close to the type of gear reduction offered by our invention is that of Keith S. Rodaway [4]. FIGS. 1-6 of Rodaway's patent shows this mechanically complex gear reduction system. It is of a differential type utilizing a ring gear with rods on its inner circumference, and an inner gear wheel with corresponding rods that rolls around on the inside of the ring gear. The eccentric rolling motion of the inner gear wheel is made to turn a central axle via a complex mechanical linkage mechanism; further, a second ring gear and inner gear wheel must be incorporated into this design to offset the eccentric motion of the first ring-wheel pair so as to eliminate vibrations caused by their offset movements. By making the number of rods on the eccentric wheels fewer than the number of rods on the surrounding ring gear, and providing an appropriate linkage mechanism to couple the differential movement of each wheel gear to a central shaft, a very high gear reduction is achieved in a single package where the gear reduction occurs as a result of the difference in circumferences of the inner wheel and the outer ring. The patent states that for a ring with A number of rods and inner wheel gear with B number of rods, the gear ratio
  R  =            B              A        -        B              .  
The speed reduction/torque enhancement method offered by the herein disclosed invention does use the subtractive difference between circumferences of a stationary “ring” (stator) and a rolling element (circular rotor band). However, the disclosed invention differs considerably in construction: (1) it is mechanically simpler, and may or may not use gear rods; (2) it employs a flexible steel band (the rotor) in place of a rolling wheel; (3) this flexible steel band (the rotor) may roll around on either the outside or the inside of the “ring gear” (stator); (4) this is not a stand-alone gear-reduction mechanism, but rather a fully integrated part of the disclosed motor/generator; and (5) instead of employing a second rotor to counterbalance off-center rolling movement, the motion of the flex rotor is balanced by bending the rotor such that it rolls along opposing symmetrical sections of the “ring gear” (stator)—magnetic stator forces are used to bend and hold the flexible rotor in specific positions such that it maintains a concentric balanced shape at all times. However, like the mechanism of Rodaway's patent, this invention can be realized employing various speed reduction ratios, and a modified version of Rodaway's gear reduction ratio employed, as the flex rotor design does not employ gear rods in all its embodiments. For full details see “Disclosure of the Elements of the System: Differential Speed-Reduction/Torque-Enhancement Embodiments;” and the Appendix for a derivation of the gear reduction equation for the flex rotor motor.
With regard to drive train mechanisms, prior art for drive trains is abundant, but none come close to suggesting the simple, fully-integrated drive train embodiments of the disclosed invention whereby differential rotor movement is mechanically linked to either a surrounding wheel rim, or to a central shaft. For details of the drive train mechanism, see “Disclosure of the Elements of the System/Integrated Drive Train Mechanism Embodiments.”
The disclosed method of quickly and efficiently transferring electrical current from one stator winding to the next in sequence around the stator herein called “current forwarding” is explained in detail in the section titled “Current Forwarding.”